What is the primary advantage of using block scope in JavaScript?
A). A. Reducing code size
B). B. Preventing variable hoisting
C). C. Avoiding global variables
D). D. Improving performance
What will be logged to the console?
A). A. 'John'
B). B. 'Jane'
C). C. Error
D). D. Undefined
Which of the following statements is true about constants declared using const?
A). A. They can be reassigned multiple times
B). B. They are hoisted to the top
C). C. They are mutable
D). D. They are immutable
Which of the following statements about const is true?
A). A. Variables declared with const can be reassigned
B). B. const variables have function scope
C). C. const variables cannot be used in loops
D). D. const variables are block-scoped
Which keyword is used to declare block-scoped variables in JavaScript?
A). A. var
B). B. let
C). C. const
D). D. block
What will be logged to the console?
A). A. 'Alice'
B). B. 'Bob'
C). C. TypeError
D). D. Undefined
What will be the output of the code above?
A). A. 30
B). B. 31
C). C. Error
D). D. Undefined
What is the purpose of using the const keyword in JavaScript?
A). A. To declare variables with global scope
B). B. To declare block-scoped variables
C). C. To declare variables that can be reassigned
D). D. To declare variables that cannot be reassigned
What will be the output of the code above?
A). A. 10
B). B. 20
C). C. Error
D). D. Undefined
What happens if you try to reassign a value to a constant declared using const?
A). A. SyntaxError
B). B. TypeError
C). C. ReferenceError
D). D. No error, value is reassigned